It does not sound like a common PCS symptom. It could be caused by an adrenal response that raises your blood pressure. Do you have a blood pressure kit? It would help if you could check your blood pressure during on of these events. You can buy them at the drug store for about $20 to $30.

If it happens when your BP rises, you can ask your doctor what to do for the rise in BP. It is not uncommon for people with PCS to have unusual and over-reactive responses to sound.

My best to you.